Flooding from excess rain or overflowing of streams and other water courses is a recurring problem. In severe emergencies, hundreds of people may construct earthworks and fill, prepare, transport and place sand bags for area-protection. However, often an individual property owner may be left to his or her own devices, with limited means and equipment. One of the primary aims of owners of homes and small businesses is to prevent flood waters from entering a building. Stacking sand bags to build a retaining wall is a familiar approach. However, pre-filled sand bags are often not readily available; and it can be a labor intensive and time consuming process to set up and fill bags, or to move heavy bags from a location where they were previously stored.
Another aim, even in non-flood conditions, is to divert the flow of water to prevent erosion. For example, in times of severe precipitation excess sheet water flow may tend to erode a sloped driveway or a garden; thus an owner may want to divert the sheet flow by laying sandbags or another temporary barrier along the ground or driveway.
Smith U.S. Pat. No. 7,762,842 shows the use of a long flexible wall impervious tube which can be filled with water to create a tubular structure which is laid on the ground to dam surface water in substitution of a conventional sand bag. The tubular structure has a weighted flap attached to the front for both anchoring of the tube and preventing flow of water under the tube. A user must pre-fill the bag with water and lay it in position to block or divert surface water. A hose is inserted into an opening or spout, to fill the bag. Doing that presumes the availability of a pressurized water supply, which could be a problem.
Doolage U.S. Pat. No. 6,783,300 discloses a surface water damming device comprised of a water filled tube that is contained within a woven fabric that provides abrasion protection. Some embodiments comprise two or more lengthwise running lobes for stability against overturning force of the dammed water.
Kataoka U.S. Pat. No. 6,524,670 discloses a coarse jute fiber bag containing a polymer resin which swells upon contact with water. The resin is contained in a water soluble pouch which is placed within an envelope of permeable fabric such as jute, commonly a coarse woven fabric. When the bag is thoroughly wetted, the pouch dissolves and the resin reacts to contact by water by expanding, to create an expanded bag which the patent misnames a sand bag. In the background section of the Kataoka patent, certain Japanese patent publication prior art is discussed, including that bags have had water expanding resin loosely contained with the sack or that resin has been pre-placed within the sack between two water absorptive sheets.
There is a need for a compact, lightweight, easy to store and easy to activate system for preventing flow of surface water into buildings and other unwanted places, and for diverting the flow of water. The system should desirably provide functionality comparable to that which might be achieved by common sandbags.